Communication between nodes for autonomic and distributed management

Over the last decade, the most widespread approaches for traditional management were based on the Simple Network Management Protocol (SNMP) or Common Management Information Protocol (CMIP). However, they both have several problems in terms of scalability, due to their centralization characteristics. Although the distributed management approaches exhibit better performance in terms of scalability, they still underperform regarding communication costs, autonomy, extensibility, exibility, robustness, and cooperation between network nodes. The cooperation between network nodes normally requires excessive overheads for synchronization and dissemination of management information in the network. For emerging dynamic and large-scale networking environments, as envisioned in Next Generation Networks (NGNs), exponential growth in the number of network devices and mobile communications and application demands is expected. Thus, a high degree of management automation is an important requirement, along with new mechanisms that promote it optimally and e ciently, taking into account the need for high cooperation between the nodes. Current approaches for self and autonomic management allow the network administrator to manage large areas, performing fast reaction and e ciently facing unexpected problems. The management functionalities should be delegated to a self-organized plane operating within the network, that decrease the network complexity and the control information ow, as opposed to centralized or external servers. This Thesis aims to propose and develop a communication framework for distributed network management which integrates a set of mechanisms for initial communication, exchange of management information, network (re) organization and data dissemination, attempting to meet the autonomic and distributed management requirements posed by NGNs. The mechanisms are lightweight and portable, and they can operate in di erent hardware architectures and include all the requirements to maintain the basis for an e cient communication between nodes in order to ensure autonomic network management. Moreover, those mechanisms were explored in diverse network conditions and events, such as device and link errors, di erent tra c/network loads and requirements. The results obtained through simulation and real experimentation show that the proposed mechanisms provide a lower convergence time, smaller overhead impact in the network, faster dissemination of management information, increase stability and quality of the nodes associations, and enable the support for e cient data information delivery in comparison to the base mechanisms analyzed. Finally, all mechanisms for communication between nodes proposed in this Thesis, that support and distribute the management information and network control functionalities, were devised and developed to operate in completely decentralized scenarios.

Quality of service in optical burst switching networks

Tese dout., Engenharia Electrónica e Computação, Universidade do Algarve, 2009

IP/optical integration in access network infrastructures: key issues on resource provisioning

This thesis contributes to the advancement of Fiber-Wireless (FiWi) access technologies, through the development of algorithms for resource allocation and energy efficient routing. FiWi access networks use both optical and wireless/cellular technologies to provide high bandwidth and ubiquity, required by users and current high demanding services. FiWi access technologies are divided in two parts. In one of the parts, fiber is brought from the central office to near the users, while in the other part wireless routers or base stations take over and provide Internet access to users. Many technologies can be used at both the optical and wireless parts, which lead to different integration and optimization problems to be solved. In this thesis, the focus will be on FiWi access networks that use a passive optical network at the optical section and a wireless mesh network at the wireless section. In such networks, two important aspects that influence network performance are: allocation of resources and traffic routing throughout the mesh section. In this thesis, both problems are addressed. A fair bandwidth allocation algorithm is developed, which provides fairness in terms of bandwidth and in terms of experienced delays among all users. As for routing, an energy efficient routing algorithm is proposed that optimizes sleeping and productive periods throughout the wireless and optical sections. To develop the stated algorithms, game theory and networks formation theory were used. These are powerful mathematical tools that can be used to solve problems involving agents with conflicting interests. Since, usually, these tools are not common knowledge, a brief survey on game theory and network formation theory is provided to explain the concepts that are used throughout the thesis. As such, this thesis also serves as a showcase on the use of game theory and network formation theory to develop new algorithms.

Radio over fiber broadband access networks architectures based on wavelength division multiplexing techniques

The recent remarkable growth in bandwidth of both wired optical and wireless access networks supports a burst of new high bandwidth Internet applications such as: peer-topeer file sharing, cloud storage, on-line gaming, video streaming, etc. Within this scenario, the convergence of fixed and wireless access networks offers significant opportunities for network operators to satisfy user demands, and simultaneously reduce the cost of implementing and running separated wireless and wired networks. The integration of wired and wireless network can be accomplished within several scenarios and at several levels. In this thesis we will focus on converged radio over fiber architectures, particularly on two application scenarios: converged optical 60 GHz wireless networks and wireless overlay backhauling over bidirectional colorless wavelength division multiplexing passive optical networks (WDM-PONs). In the first application scenario, optical 60 GHz signal generation using external modulation of an optical carrier by means of lithium niobate (LiNbO3) Mach- Zehnder modulators (MZM) is considered. The performance of different optical modulation techniques, robust against fiber dispersion is assessed and dispersion mitigation strategies are identified. The study is extended to 60 GHz carriers digitally modulated with data and to systems employing subcarrier multiplexed (SCM) mm-wave channels. In the second application scenario, the performance of WDM-PONs employing reflective semiconductor optical amplifiers (RSOAs), transmitting an overlay orthogonal frequency-division multiplexing (OFDM) wireless signal is assessed analytically and experimentally, with the relevant system impairments being identified. It is demonstrated that the intermodulation due to the beating of the baseband signal and wireless signal at the receiver can seriously impair the wireless channel. Performance degradation of the wireless channel caused by the RSOA gain modulation owing to the downstream baseband data is also assessed, and system design guidelines are provided.

Desenvolvimento de esquemas de ensino baseados na WWW

Dissertação de mestrado, Engenharia de Sistemas e Computação, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2001

Monitoring of urban transportation networks using wireless sensor networks

Dissertação de mestrado, Engenharia Informática, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

Data storage system for wireless sensor networks

Dissertação de mestrado, Engenharia Informática, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

Relatório da Prática de Ensino Supervisionada do mestrado em Ensino de Informática no 3.º ciclo do Ensino Básico e no Ensino Secundário

Dissertação de mestrado, Ensino de Informática no 3.º Ciclo do Ensino Básico e no Ensino Secundário, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2014

Relatório da Prática de Ensino Supervisionada do mestrado em Ensino de Informática no 3.º ciclo do Ensino Básico e no Ensino Secundário

Dissertação de mestrado, Ensino de Informática no 3.º Ciclo do Ensino Básico e no Ensino Secundário, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2014

Benchmarking de uma aproximação de ticketing as a service (Taas)

Dissertação de natureza científica realizada para obtenção do grau de Mestre em Engenharia de Redes de Computadores e Multimédia

Biblioteca Digital Colombiana: estrategia hacia el acceso abierto

Primera conferencia. Bibliotecas y Repositorios Digitales: Gestión del Conocimiento, Acceso Abierto y Visibilidad Latinoamericana. (BIREDIAL) Mayo 9 al 11 de 2011. Bogotá, Colombia.

Las tecnologías "PEER-TO-PEER" los derechos de autor y el "COPYRIGHT"

William Murray fue un jurista singular. Con el nombre literario de Lord Mansfield, creó para su época y para la posteridad una expresión inolvidable: ―Una persona puede usar una copia tocándola, pero no tiene ningún derecho a robarle al autor los beneficios multiplicando las copias y disponiendo de ellas para su propio uso‖1 . En esa opinión se apoyó para decidir el memorable caso de Millar v. Taylor2, donde por primera vez se sostuvo que los derechos de autor son perpetuos y nunca entran a hacer parte del dominio público. La disputa involucraba a Andrew Millar, un vendedor de libros que, en 1729, adquirió los derechos de edición sobre ‗The Seasons’, un poema de James Thomson. Cuando la protección de esos derechos expiró, Robert Taylor comenzó a publicar sus propias copias y a competir con Millar.

Diseño de una red que permita la comunicación del Instituto Nacional de Medicina Legal y Ciencias Forenses. Prueba piloto Bogotá - Medellín

El presente proyecto presenta una alternativa para diseñar la infraestructuratecnológica de redes y seguridad informática a nivel nacional que le permita alInstituto Nacional de Medicina Legal y Ciencias Forenses garantizar la seguridadde transmisión de datos y oportunidad de la informaci

Diseño e implementación de un sistema de acceso global y de almacenamiento

CHENSON debe garantizar a la población de Bogotá D.C. el derecho ala salud, consagrado en la Constitución Política de Colombia de 1991,con equidad y universalidad conforme a las necesidades poblacionalespor territorios sociales, en la búsqueda del desarrollo y la preservaciónde la autonomía

Evolución de Red - Acceso IP

La forma en que las Compañías implantan su estrategia es a través deproyectos. Así surge la idea del proyecto como “una combinación de todoslos recursos en una organización temporal para la transformación de unaidea en una realidad”1. En la medida en la que la ejecución de los proyectossea exitosa, será la medida en la que se habrá implantado con éxito laestrategia de la compañía